Not the best I know, but what really got me is having to photograph the background behind the tracing paper.
In today's world of 2d Animation, if I want to hand paint or draw a background, as well as the character lines and colors traditionally, how would I accomplish this?
I understand how it worked with cells, but I know they're not used anymore.

If that's what you want to do, you could get a registration bar, for one. That's cheap, and will help. You can just tape one on to your lightbox.

A bunch of frames from a still camera works too. Scanning into TVPaint is probably the better thing to do. You can align to registration holes and all too. Where on the planet are you (country?) There are a number of animation suppliers out there.

In TVPaint, you just draw on different 'layers'. Very doable, it's sort of like an electronic stack of cels. Imported images work the same way. Easy to deal with.

>formerly User 767: "It seems your login has been deleted. Your login being a little strange, maybe you have written a strange post and we thought your were a bot."
Heaven forbid that an animator might be 'strange'